Abstract In this project, Perspectum Diagnostics seeks to complete the necessary evidence to qualify the MRI imaging biomarkers iron-corrected T1 (cT1) and PDFF as Drug Development Tools for NASH. Both cT1 and PDFF show promise as diagnostic enrichment biomarkers. They are envisioned to be used in in conjunction with clinical risk factors, to identify patients who are more likely to have liver histopathologic findings appropriate for inclusion in non-alcoholic steatohepatitis (NASH) clinical trials. We also believe that they both have potential as pharmaco-dynamic efficacy biomarkers to be used as endpoints in clinical trials. With the funding from this U01 Cooperative Agreement proposal and leveraging the close collaboration with the FDA, we will perform a biopsy-paired case-control observational study in 60 patients. The aims of this study are two-fold and interdependent: To demonstrate that a binary decision algorithm applied to cT1 (and/or PDFF) can significantly identify patients whose liver biopsy results would qualify them for randomization in a clinical trial testing an investigational treatment for NASH with fibrosis To determine the measurement repeatability of cT1 and PDFF in the target patient population by examining the test-retest variability, with the ultimate objective to establish agreement around tightly defined cut-offs. The study will be performed by the Texas Liver Institute who will include a representative sample of their patient population over a period of 6 months.